1. In some trains you can't even use your mobile phones! 在一些火车上你甚至都不能用你的移动电话!
2. It refers to not only people but also camera phones and other similar devices. 它所指的不但是人,也可以指照相手机和其他相似的器材。
3. Activists fight for different things. But one thing many activists around the world hold in common is their use of mobile phones as a tool for their work. 活动家们为不同的事业奋斗。但有一件事是世界各地许多活动家共同所有的。这就是他们都用移动电话作为活动工具。